The present invention relates to an adjustable double-roller oil feeder which can be installed in a horizontal position, or tilted sideways by changing the position of the oil intake pipe thereof, or tilted backwards by attaching curved oil guide tubes to the oil drain holes on the transverse top frame thereof for guiding the lubricating oil to the first roller thereof. Springs are installed to support the rollers so that shocks are eliminated or lessened as the workpiece passes through the gap between the first and second rollers of the oil feeder.
A punching metal-working machine generally has an oil feeder to apply a lubricating oil to the workpiece being processed so as to reduce the working temperature and prolong the service life of the machine. There is a double-roller type oil feeder disclosed for this purpose. This double-roller type oil feeder, as shown in FIG. 7, comprises an upper roller (2A) having a center tube (21A), a lower roller (3A) having a center tube (31A), an oil tank (11A) controlled by a control valve (12A) to supply a lubricating oil to the center tubes (21A;31A) of the upper and lower rollers (2A;3A) through an oil supply pipe (1A). The center tubes (21A;31A) of the upper and lower rollers (2A;3A) have respective oil outlets (211A;311A) of a uniform size, each being received in a respective sleeve (22A;32A). The sleeves (22A;32A) have equally spaced oil drain holes (221A;321A), each being covered with a respective cylindrical covering layer (23A;33A). The cylindrical covering layer (23A;33A) is respectively made of fibers, sponge, etc. During the operation of the oil feeder, the workpiece is moved through the gap between the upper roller (2A) and the lower roller (3A). The lubricating oil which is guided into the center tubes (21A;31A) flows out of the oil outlets (211A;311A) and the oil drain holes (221A;321A) to permeate the covering layers (23A;33A), and therefore the lubricating oil is covered over the two opposite sides of the workpiece to reduce the working temperature as the workpiece passes through the upper and lower rollers (2A;3A). This structure of double-roller oil feeder is still not satisfactory in function. The drawbacks of this structure of double-roller oil feeder are numerous and outlined hereinafter.
i) The lubricating oil can not be uniformly applied to the covering layers (23A;33A). As the lubricating oil is viscous, it cannot quickly fill up the inside space of the center tube (21A;31A). Because the oil outlets (211A;311A) are equal in diameter, much volume of the lubricating oil flows out of the oil outlets near the oil input side, and less volume of the lubricating oil flows out of the oil outlets far from the oil input side. Because the oil drain holes (221A;321A) are equally spaced on the sleeves (22A;32A), the lubricating oil cannot be uniformly distributed over the inside wall of the covering layers (23A;33A), and less volume of the lubricating oil is applied to the area between either two oil drain holes (221A;321A). PA1 ii) The volume of the supply of the lubricating oil through either oil outlets (211A;311A) cannot be respectively regulated. The regulation of the supply of the lubricating oil is controlled by the control valve (12A). However, the control valve (12A) can only regulate the total volume of the supply of the lubricating oil. In case the oil supply pipe (1A) is partially blocked, the intake volume of the lubricating oil for applying to the covering layers (23A;33A) becomes unstable, and there workpiece cannot be uniformly covered with the lubricating oil. PA1 iii) The oil feeder must be installed in a horizontal position so that the lubricating oil can be smoothly applied to the workpiece. If the oil feeder is installed in a tilted position, the lubricating oil will be accumulated in the rollers (2A;3A), and the application of the lubricating oil to the workpiece will become unstable.